Psychology ETDs

Publication Date

3-14-1979

Abstract

The long-term effects of early social isolation in rhesus monkeys have been assumed to be highly similar to those found in young, subadult isolation reared monkeys. Typical methodologies involved the observation of social behavior during brief "encounter" tests. Recent evidence suggests that this procedure may well have obscured important developmental effects. The purpose of the present study was to evaluate the social behavior repetoires of fully adult, differentially reared, rhesus monkeys in brief encounter and continuous social contact environmental situations. In a previous study, six monkeys reared for the first 9 months of life in total social isolation, and six control animals, all having a mean age of 11 years, were placed in separate social groups and observed. In the present study, the members of each of these groups were introduced, in dyadic pairings, to a male and female stranger monkey in a playroom. Following these pairings, both groups were merged into one large group and lived together for 20 weeks. The behavior of each individual monkey was followed over the 20-week mixed housing through the use of a 27 category modified frequency scoring system. Each monkey was scored three times per week for 3 minutes. In addition, 11 times during the 20-week period, the entire group was observed as they competed for access to a highly preferred drink. At the end of the 20-week mixed housing, the six adult isolation-reared monkeys and the six adult controls were again compared in their response to adult male and female stranger monkeys. The isolates were then formed into a separate group and observed for 4 weeks. The results of the present study suggest three main findings. First, as a function of the mixed housing experience, isolation reared monkeys showed significant decreases in self-directed behaviors and a linear increase in the levels of passive social behavior observed. Second, although the isolates failed to differ with statistical significance across the pretests and posttests, the profile of their behavioral repertoire changed markedly between the two tests. When consideration was given to the direction of the change, marginal significance was obtained. Probably the most important change of the pre- and post-tests was the dramatic increase in social behavior. Grooming behavior, which was seen at a rate of once per one hundred observations of the group in the pretest period, increased to a rate of seven out of every ten group observations in the posttest. Similarly, passive social behavior increased 47% across the two tests. While not statistically significant, these changes do represent important changes in the behavior of the isolates. Bearing in mind the difficulties of finding significance with such a small sample, and the nature of the changes observed in the isolates' behavior, the present study clearly suggests that the changes observed in the isolates' behavior are attributable to the mixed housing experience.

Degree Name

Psychology

Level of Degree

Doctoral

Department Name

Psychology

First Committee Member (Chair)

John Paul Gluck Jr.

Second Committee Member

Francis S. Harnick

Third Committee Member

Sidney Rosenblum

Fourth Committee Member

Britton Kenneth Ruebush

Language

English

Document Type

Dissertation

Download

Included in

Psychology Commons

Share

COinS